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Deyong Shao - One of the best experts on this subject based on the ideXlab platform.
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pore types and pore network evolution in upper devonian lower mississippian woodford and mississippian barnett Mudstones insights from laboratory thermal maturation and organic petrology
International Journal of Coal Geology, 2017Co-Authors: Lucy T Ko, Robert G Loucks, Stephen C Ruppel, Paul C Hackley, Tongwei Zhang, Deyong ShaoAbstract:Abstract Pore-evolution models from immature organic-matter (OM) -rich Barnett (0.42%R o ) and Woodford (0.49%R o ) Mudstones were compared with models previously developed from low-maturity OM-lean Boquillas (Eagle Ford-equivalent) Mudstones to investigate whether (1) different mineralogy (siliceous vs. calcareous) exerts different catalytic and sorption effects and influences OM-pore origin and evolution; and (2) different types of macerals show different OM pore evolution history. Laboratory gold-tube pyrolysis, scanning electron microscopy (SEM) and thin-section petrography, organic petrography, and geochemical characterization were used to investigate the role of bulk mineralogy, maceral type, and thermal maturation on OM-pore evolution. Results suggest that mineralogy has little impact on OM-pore development and evolution. Macerals, identified using both SEM (platy OM, particulate OM, organic–mineral admixtures, Tasmanites ) and organic petrology (vitrinite, inertinite, amorphous organic matter [AOM]/bituminite, telalginite [ Leiosphaeridia , Tasmanites ]), do affect the origin and evolution of OM pores owing to differences in chemical compositions, generation kinetics, and activation-energy distributions between Tasmanites , matrix bituminite, and other types of macerals. Leiosphaeridia and Tasmanites in Woodford mudstone samples exhibit a delay in onset and a shorter period of petroleum generation and pore development compared to the matrix bituminite in the Barnett and Woodford mudstone samples. Pre-oil solid bitumen was observed to have migrated into initial primary mineral pore networks at the bitumen generation stage in both Barnett and Woodford samples. At higher levels of thermal maturation, the volume of primary mineral pores decreases and the pore volume composed of modified mineral pores and OM pores becomes greater. Pore evolution and pore-type heterogeneity in these Mudstones is a function of the initial mineral pore network, types of kerogen and macerals, and generation kinetics of individual macerals upon thermal maturation.
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pore types and pore network evolution in upper devonian lower mississippian woodford and mississippian barnett Mudstones insights from laboratory thermal maturation and organic petrology
International Journal of Coal Geology, 2017Co-Authors: Stephen C Ruppel, Robert G Loucks, Paul C Hackley, Tongwei Zhang, Deyong ShaoAbstract:Abstract Pore-evolution models from immature organic-matter (OM) -rich Barnett (0.42%R o ) and Woodford (0.49%R o ) Mudstones were compared with models previously developed from low-maturity OM-lean Boquillas (Eagle Ford-equivalent) Mudstones to investigate whether (1) different mineralogy (siliceous vs. calcareous) exerts different catalytic and sorption effects and influences OM-pore origin and evolution; and (2) different types of macerals show different OM pore evolution history. Laboratory gold-tube pyrolysis, scanning electron microscopy (SEM) and thin-section petrography, organic petrography, and geochemical characterization were used to investigate the role of bulk mineralogy, maceral type, and thermal maturation on OM-pore evolution. Results suggest that mineralogy has little impact on OM-pore development and evolution. Macerals, identified using both SEM (platy OM, particulate OM, organic–mineral admixtures, Tasmanites ) and organic petrology (vitrinite, inertinite, amorphous organic matter [AOM]/bituminite, telalginite [ Leiosphaeridia , Tasmanites ]), do affect the origin and evolution of OM pores owing to differences in chemical compositions, generation kinetics, and activation-energy distributions between Tasmanites , matrix bituminite, and other types of macerals. Leiosphaeridia and Tasmanites in Woodford mudstone samples exhibit a delay in onset and a shorter period of petroleum generation and pore development compared to the matrix bituminite in the Barnett and Woodford mudstone samples. Pre-oil solid bitumen was observed to have migrated into initial primary mineral pore networks at the bitumen generation stage in both Barnett and Woodford samples. At higher levels of thermal maturation, the volume of primary mineral pores decreases and the pore volume composed of modified mineral pores and OM pores becomes greater. Pore evolution and pore-type heterogeneity in these Mudstones is a function of the initial mineral pore network, types of kerogen and macerals, and generation kinetics of individual macerals upon thermal maturation.
Knut Bjørlykke - One of the best experts on this subject based on the ideXlab platform.
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Permeability Anisotropy in Synthetic Mudstones − An Experimental Study
73rd EAGE Conference and Exhibition incorporating SPE EUROPEC 2011, 2011Co-Authors: Nazmul Haque Mondol, Jens Jahren, T. Berre, L. Grande, Knut BjørlykkeAbstract:This study investigates permeability anisotropy in well characterized synthetic Mudstones. A total of 10 brine-saturated synthetic Mudstones of varying textural and mineralogical compositions were compacted in a triaxial cell (K0-consolidation) while the vertical and horizontal permeability were measured at different stress levels. The results show that the vertical and horizontal permeabilities of synthetic Mudstones differ by as much as 5-6 orders of magnitude as a function of mineralogy at the same stress level. Permeabilities were isotropic in pure silt but adding about 30% clays to the silt strongly reduced the permeability and increased the anisotropy. The horizontal-to-vertical permeability ratio in silt-clay and clay-clay mixtures varies from 0.5 to 3.5, demonstrating the importance of clay mineralogy, grain size and silt content on permeability anisotropy development in Mudstones. Natural mudstone may have much higher permeability anisotropy than found in this study due to a primary depositional lamination and bedding on larger scale than produced in the laboratory. Permeability distributions and horizontal-to-vertical permeability ratios derived in this study can readily be tested on cap rocks and used to model fluid flow where the compaction is mostly mechanical. At greater depth chemical compaction may increase the permeability anisotropy of mudstone further.
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physical properties of cenozoic Mudstones from the northern north sea impact of clay mineralogy on compaction trends
AAPG Bulletin, 2009Co-Authors: Oyvind Marcussen, Jens Jahren, Knut Bjørlykke, B Thyberg, Christer Peltonen, Jan Inge FaleideAbstract:Vertical and lateral changes in physical properties in Cenozoic Mudstones from the northern North Sea Basin reflect differences in the primary mineralogical composition and burial history, which provides information about sedimentary facies and provenance. Integration of well-log data with mineralogical information shows the effect of varying clay mineralogy on compaction curves in Mudstones. The main controlling factor for the compaction of Eocene to early Miocene Mudstones within the North Sea is the smectite content, which is derived from volcanic sources located northwest of the North Sea. Mudstones with high smectite content are characterized by low P-wave velocities and bulk densities compared to Mudstones with other clay mineral assemblages at the same burial depths. Smectitic clays are important during mechanical compaction because they are less compressible than other types of clay minerals. A comparison between well-log data and experimental work also shows that smectite may be a controlling factor for overpressure generation in the smectite-rich Eocene and Oligocene sediments. At greater burial depths and temperatures (70–80C), the dissolution of smectite and precipitation of illite and quartz significantly increases velocities and densities. Miocene and younger Mudstones from the northern North Sea have generally low smectite contents and as a result have higher velocities and densities than Eocene and Oligocene Mudstones. Lateral differences in the compaction trends between the north and south for these sediments also exist, which may be related to two different source areas in the Pliocene. The log-derived petrophysical data from the northern North Sea Basin show that mudstone lithologies have very different compaction trends depending on the primary composition. Simplified compaction curves may therefore affect the outcomes from basin modeling. The amplitude-versus-offset response of hydrocarbon sands and the seismic signature on seismic sections are also dependent on the petrophysical properties of Mudstones and will vary depending on the mineralogical composition.
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Synthetic mudstone compaction trends and their use in pore pressure prediction
First Break, 2008Co-Authors: Nazmul Haque Mondol, Manzar Fawad, Jens Jahren, Knut BjørlykkeAbstract:We have compared compaction trends for synthetic Mudstones to well logs in order to predict pore pressure in shallow mudstone sequences in the northern North Sea and Voring Basin, offshore Norway. Well log data showing intervals of higher porosity and lower density than the experimental data may indicate significant overpressure development. The variability found within mudstone compaction trends indicates that mechanical compaction of Mudstones varies over a wide range depending on clay mineral type (smectite, kaolinite, chlorite, illite, etc.), particle size, the total amount of clays, sand and silt particles (quartz, feldspar, mica, etc.), nature of pore fluids, and pore pressure. Smectite has low ompressibility, velocity, and permeability compared to other clay minerals. The key to successful application of compaction trends to pore pressure prediction, therefore, must be lithological and textural characterization of the individual Mudstones. These parameters are predominantly controlled by provenance, facies, and depositional history. This study demonstrates that experimental compaction trends of well characterized synthetic Mudstones can be a useful tool to predict pore pressure during shallow burial where mechanical compaction is the dominant process.
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mineralogical control on mudstone compaction a study of late cretaceous to early tertiary Mudstones of the voring and more basins norwegian sea
Petroleum Geoscience, 2008Co-Authors: Christer Peltonen, Oyvind Marcussen, Knut Bjørlykke, Jens JahrenAbstract:The Late Cretaceous to Early Tertiary sediments of the Voring and More basins are predominantly composed of fine-grained Mudstones. Variations in the mineralogy and chemistry of these Mudstones provide information regarding facies, provenance and burial history, and may also be used to predict rock properties. Over 300 cuttings’ samples from five wells were analysed by XRD. The results show significant changes in mineralogy as a function of burial depth, as well as important lateral variations throughout the basins. Eocene Mudstones with up to 55% smectite probably represent a northern equivalent of the Balder Formation (North Sea). The underlying Late Cretaceous sequence probably had less primary smectite derived from volcanic ash, as indicated by the lower iron content. The distribution of smectite is also limited by its thermal stability, thus providing important constraints on the temperature history. These mudstone sequences may appear to be relatively homogeneous based on gamma-ray and shale volume calculations from wireline logs, but mineralogical and geochemical analyses from cuttings show that they vary significantly in composition. The smectite content is greatest in the south ( c . 55%) and decreases significantly northward ( c . 20%), indicating a marked regional control on velocity/porosity–depth curves. Mudstones containing high smectite content are characterized by lower velocities, lower densities and higher porosities when compared with published burial curves. Stratigraphic and regional variations in velocity and density are important for seismic interpretation and are significant for basin modelling.
Timothy M Demko - One of the best experts on this subject based on the ideXlab platform.
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parasequence types in shelfal mudstone strata quantitative observations of lithofacies and stacking patterns and conceptual link to modern depositional regimes
Geology, 2014Co-Authors: Kevin M Bohacs, Remus O Lazar, Timothy M DemkoAbstract:Mudstone strata have a vast variety of physical, biogenic, and chemical attributes at the lamina to bed scale (approximately millimeters to decimeters thick). Our observations of more than 7 km of Paleozoic to Cenozoic Mudstones revealed ordered patterns in this variety, i.e., recurrent associations of lithofacies, bedding style, sedimentary structures, and stratal architecture at bedset to parasequence scales (approximately decimeters to meters thick). We quantified characteristics of each association and their stacking patterns in vertical succession and linked them to sets of depositional processes. Most shelf mudstone strata appear to have accumulated in one of three facies association successions (FASs) that can be related to depositional regimes through characteristic modes of sediment transport and accumulation, as well as variations in benthic-energy and oxygen levels. We interpret these three FASs as records of mud accumulation on different portions of continental shelves that were dominated by storm waves, river floods, or tidal currents. Each FAS records a distinct parasequence type. This approach can help fully integrate insights from oceanographic studies into more robust interpretations of the rock record and rock-property maps.
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Parasequence types in shelfal mudstone strata—Quantitative observations of lithofacies and stacking patterns, and conceptual link to modern depositional regimes
Geology, 2014Co-Authors: Kevin M Bohacs, O. Remus Lazar, Timothy M DemkoAbstract:Mudstone strata have a vast variety of physical, biogenic, and chemical attributes at the lamina to bed scale (approximately millimeters to decimeters thick). Our observations of more than 7 km of Paleozoic to Cenozoic Mudstones revealed ordered patterns in this variety, i.e., recurrent associations of lithofacies, bedding style, sedimentary structures, and stratal architecture at bedset to parasequence scales (approximately decimeters to meters thick). We quantified characteristics of each association and their stacking patterns in vertical succession and linked them to sets of depositional processes. Most shelf mudstone strata appear to have accumulated in one of three facies association successions (FASs) that can be related to depositional regimes through characteristic modes of sediment transport and accumulation, as well as variations in benthic-energy and oxygen levels. We interpret these three FASs as records of mud accumulation on different portions of continental shelves that were dominated by storm waves, river floods, or tidal currents. Each FAS records a distinct parasequence type. This approach can help fully integrate insights from oceanographic studies into more robust interpretations of the rock record and rock-property maps.
Robert G Loucks - One of the best experts on this subject based on the ideXlab platform.
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pore types and pore network evolution in upper devonian lower mississippian woodford and mississippian barnett Mudstones insights from laboratory thermal maturation and organic petrology
International Journal of Coal Geology, 2017Co-Authors: Stephen C Ruppel, Robert G Loucks, Paul C Hackley, Tongwei Zhang, Deyong ShaoAbstract:Abstract Pore-evolution models from immature organic-matter (OM) -rich Barnett (0.42%R o ) and Woodford (0.49%R o ) Mudstones were compared with models previously developed from low-maturity OM-lean Boquillas (Eagle Ford-equivalent) Mudstones to investigate whether (1) different mineralogy (siliceous vs. calcareous) exerts different catalytic and sorption effects and influences OM-pore origin and evolution; and (2) different types of macerals show different OM pore evolution history. Laboratory gold-tube pyrolysis, scanning electron microscopy (SEM) and thin-section petrography, organic petrography, and geochemical characterization were used to investigate the role of bulk mineralogy, maceral type, and thermal maturation on OM-pore evolution. Results suggest that mineralogy has little impact on OM-pore development and evolution. Macerals, identified using both SEM (platy OM, particulate OM, organic–mineral admixtures, Tasmanites ) and organic petrology (vitrinite, inertinite, amorphous organic matter [AOM]/bituminite, telalginite [ Leiosphaeridia , Tasmanites ]), do affect the origin and evolution of OM pores owing to differences in chemical compositions, generation kinetics, and activation-energy distributions between Tasmanites , matrix bituminite, and other types of macerals. Leiosphaeridia and Tasmanites in Woodford mudstone samples exhibit a delay in onset and a shorter period of petroleum generation and pore development compared to the matrix bituminite in the Barnett and Woodford mudstone samples. Pre-oil solid bitumen was observed to have migrated into initial primary mineral pore networks at the bitumen generation stage in both Barnett and Woodford samples. At higher levels of thermal maturation, the volume of primary mineral pores decreases and the pore volume composed of modified mineral pores and OM pores becomes greater. Pore evolution and pore-type heterogeneity in these Mudstones is a function of the initial mineral pore network, types of kerogen and macerals, and generation kinetics of individual macerals upon thermal maturation.
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pore types and pore network evolution in upper devonian lower mississippian woodford and mississippian barnett Mudstones insights from laboratory thermal maturation and organic petrology
International Journal of Coal Geology, 2017Co-Authors: Lucy T Ko, Robert G Loucks, Stephen C Ruppel, Paul C Hackley, Tongwei Zhang, Deyong ShaoAbstract:Abstract Pore-evolution models from immature organic-matter (OM) -rich Barnett (0.42%R o ) and Woodford (0.49%R o ) Mudstones were compared with models previously developed from low-maturity OM-lean Boquillas (Eagle Ford-equivalent) Mudstones to investigate whether (1) different mineralogy (siliceous vs. calcareous) exerts different catalytic and sorption effects and influences OM-pore origin and evolution; and (2) different types of macerals show different OM pore evolution history. Laboratory gold-tube pyrolysis, scanning electron microscopy (SEM) and thin-section petrography, organic petrography, and geochemical characterization were used to investigate the role of bulk mineralogy, maceral type, and thermal maturation on OM-pore evolution. Results suggest that mineralogy has little impact on OM-pore development and evolution. Macerals, identified using both SEM (platy OM, particulate OM, organic–mineral admixtures, Tasmanites ) and organic petrology (vitrinite, inertinite, amorphous organic matter [AOM]/bituminite, telalginite [ Leiosphaeridia , Tasmanites ]), do affect the origin and evolution of OM pores owing to differences in chemical compositions, generation kinetics, and activation-energy distributions between Tasmanites , matrix bituminite, and other types of macerals. Leiosphaeridia and Tasmanites in Woodford mudstone samples exhibit a delay in onset and a shorter period of petroleum generation and pore development compared to the matrix bituminite in the Barnett and Woodford mudstone samples. Pre-oil solid bitumen was observed to have migrated into initial primary mineral pore networks at the bitumen generation stage in both Barnett and Woodford samples. At higher levels of thermal maturation, the volume of primary mineral pores decreases and the pore volume composed of modified mineral pores and OM pores becomes greater. Pore evolution and pore-type heterogeneity in these Mudstones is a function of the initial mineral pore network, types of kerogen and macerals, and generation kinetics of individual macerals upon thermal maturation.
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open system chemical behavior in deep wilcox group Mudstones texas gulf coast usa
Marine and Petroleum Geology, 2010Co-Authors: Ruarri J Daystirrat, Andrew C Aplin, Kitty L Milliken, Shirley P Dutton, Robert G Loucks, S J Hillier, Anja M SchleicherAbstract:Abstract Wilcox Group Mudstones have been mechanically and geochemically transformed over a temperature range of 20–200 °C. Our research controlled for provenance and age by sampling from five wells, parallel to the paleodepositional axis, all within the Houston delta system. Across the sampled depths, mudstone porosity has been reduced from ∼25 to
Stephen J. Piercey - One of the best experts on this subject based on the ideXlab platform.
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Geology and lithogeochemistry of hydrothermal Mudstones from the upper block near the Duck Pond volcanogenic massive sulfide (VMS) deposit, Newfoundland, Canada: evidence for low-temperature venting into oxygenated mid-Cambrian seawater
Mineralium Deposita, 2018Co-Authors: Stephen J. Piercey, Gerry Squires, Terry BraceAbstract:Pyrite- and pyrrhotite-rich Mudstones are spatially associated with Cambrian (~ 512–509 Ma) volcanogenic massive sulfide (VMS) deposits throughout the Tally Pond group, central Newfoundland, Canada. At the Duck Pond mine, sulfide-rich Mudstones are hosted within a weakly mineralized upper block that structurally overlies the deposit but is older (~ 513 versus 509 Ma). The Mudstones are laminated, 10–30-cm thick, and pyrite- and pyrrhotite-rich and occur along pillow lava selvages, or in between pillow lavas, rhyolite flows, and volcaniclastic rocks. The Mudstones are laterally extensive and proximal to the mudstone host rocks are hydrothermally altered to epidote-quartz-chlorite (basalt host) and sericite-quartz (rhyolite host). Lithogeochemical data for the sulfide-rich Mudstones reflect the varying contributions of elements from sedimentary detritus, hydrothermal discharge, and hydrogenous scavenging from middle Cambrian seawater. The Mudstones have minor detrital element abundances and significant hydrothermal element enrichments (i.e., elevated Fe_2O_3, S, Pb, Zn, Cu, and Ba concentrations, high Fe/Al ratios). The hydrothermal Mudstones are also enriched in oxyanions (i.e., P_2O_5, U, V, Cr, Ni, Co, and Hg), interpreted to have been enriched via oxidative scavenging from seawater by Fe-oxide/oxyhydroxide particles. The Mudstones also have REE-Y signatures similar to modern oxygenated seawater with high Y/Ho and negative Ce anomalies (Ce/Ce* = 0.40–0.86; average = 0.58), which correlate with adsorbed oxyanion concentrations. The low Eu/Eu* (1.02–1.86; average = 1.22) in the Mudstones suggest that they were deposited from low-temperature (
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geology mineralogy and lithogeochemistry of metalliferous Mudstones associated with the lemarchant volcanogenic massive sulfide deposit tally pond belt central newfoundland
Economic Geology, 2015Co-Authors: Stefanie Lode, Stephen J. Piercey, Christine A DevineAbstract:The Cambrian Lemarchant Zn-Pb-Cu-(Au-Ag) bimodal felsic volcanogenic massive sulfide (VMS) deposit, Tally Pond group, central Newfoundland, Canada, contains metalliferous Mudstones that occur either immediately on top or laterally along strike from massive sulfide mineralization, or as interflow Mudstones within hanging-wall basaltic rocks. The Mudstones are brown to black, graphite rich, and locally have intercalations of siliciclastic, volcaniclastic and/or amorphous chert layers, and, in some cases, fine lamina of organic matter. The main sulfide phases are pyrite (framboidal and euhedral) and pyrrhotite, with minor chalcopyrite, sphalerite, arsenopyrite, and galena; barite is a common sulfate. The metalliferous Mudstones occur at various stratigraphic levels and have variable inputs of hydrothermal (high Fe/Al and base metal values) and detrital components (lower Fe/Al and base metal values) with positive shale normalized Eu anomalies (Eu/Eu* ≥1), negative Ce anomalies (Ce/Ce* ≤1), and an average Y/Ho ratio of ~28.3. These signatures suggest precipitation from reduced, high-temperature hydrothermal vent fluids in an oxygenated water column, coupled with the hydrothermal particles having a short residence time within the hydrothermal plume (i.e., a vent proximal setting). Deposition from an oxygenated water column is also supported by the presence of abundant barite in both the Lemarchant massive sulfides and the metalliferous Mudstones, as well as locally preserved marcasite in the Mudstones. Redox-sensitive trace elements (As, U, V, Mo, Cr, Ni, and Co) were scavenged as oxyanions onto Fe oxyhydroxides during mudstone formation, and these elevated levels of scavenged redox-sensitive trace elements cause apparent anoxic signatures. Immobile element systematics (La-Th-Zr/10 and Th-La-Sc) indicate that the detrital components of the Lemarchant Mudstones were mixtures of both continental and mafic sources, most likely deposited within a pericontinental rifted arc environment. Our research illustrates that the lithogeochemistry of metalliferous Mudstones can identify vent proximity and provides insights into the physiochemical conditions of the deposit formation and the ambient environment. These results have implications for similar precious metal-bearing VMS deposits globally.